Cooling fan with dynamic and static blades

ABSTRACT

A cooling fan with dynamic and static blades includes a fan and a static blade device. The fan has a fan frame with two lateral sides forming an inlet and an outlet respectively and provides dynamic blades in the fan frame. The static blades are mounted at the outlet and extend into the outlet of fan frame to reduce distance between the dynamic blades and the static blades for saving space thereof.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is related to a cooling fan with dynamic andstatic blades and particularly to a fan in which the dynamic bladesbeing arranged to separate from the static blades.

2. Brief Description of the Related Art

The conventional axial flow fan can be divided into single stage bladetype and double stage blade type. The axial flow fan with single stageblades is a fan with dynamic blades and the axial flow fan with doublestage blades is a fan with dynamic blades integrally arranged withstatic blades for offering fluid a propelling force by way of thedynamic and static blades rotating with the fan shaft.

The preceding fan with dynamic blades provides the outward direction ofair flow has to be inclining with the axis of the fan based on theprinciple of fluid mechanics such that the outward fluid flowsdivergently instead of being concentrative. In this way, the directionof air flowing is inconsistent with the cooling fins and it results inincreasing resistance and lowering air flow passing through the coolingfins such that unfavorable heat dissipation effect with loud noise isobtained.

The fan with dynamic blades integral with static blades improves thedeficiency of the dynamic blade fan and a static blade stage is added inthe fan at the rear side of the dynamic blades. The hollow frame of thefan is shared with the dynamic blades and the static blades and thestatic blades are able to rectify the diverging air flow from thedynamic blades to concentrate the air flow outward the fan. In this way,the direction of air flow is approximately parallel to the axialdirection of the fan and consistent with the direction of the coolingfan for increasing air flow passing through the cooling fins andattenuating noise.

However, the fan with dynamic blades integral with static blades stillfaces many problems in practice. Due to the dynamic blades beingarranged integrally with the static blades, the fan is suitable forbeing operated in a specific environment only in order to maintainfavorable work condition, high efficiency, sufficient flow rate and lownoise. Further, either the dynamic blades or the static blades isdamaged, both the blades have to be replaced at the same time such thathigh maintenance and repair costs results in a great burden to the user.

Taiwanese Patent Official Gazette No. 488497 entitled FAN WITHSUPERCHARGING FLOW GUIDE DEVICE Referring and No. 523652 entitledCOMPOSITE FAN WITH FAN FRAME disclose the static blades are disposed toseparate from the dynamic blades for promoting air flow rate and airpressure and suitable for different environment needs.

The problem of the preceding prior art is in that a large distance iscreated between the dynamic blades and the static blades afterassembling to each other and it reduces kinetic energy of the fluid. Aclearance between the assembled parts leads the fluid to overflow beforereaching the static blades and it is unfavorable for increasing airpressure.

SUMMARY OF THE INVENTION

A main object of the present invention is to a cooling fan with dynamicand static blades in which the static blades are independent from thedynamic blades and extend toward the dynamic blades to shorten distancebetween them and to save the space of the fan.

In order to achieve the preceding object, the cooling fan with dynamicand static blade includes a fan, having a fan frame with a hollow flowpassage, the flow passage having an inlet at a lateral side of the fanand an outlet at another lateral side of the fan frame; a support seat,being disposed near the outlet and joined with a plurality of dynamicblades; and at least a static blade device, being mounted to the outlet,providing a hollow frame member with a plurality of static blades, thestatic blades extending axially toward one of the lateral sides and intothe outlet for reducing a space between the dynamic blades and thestatic blades.

BRIEF DESCRIPTION OF THE DRAWINGS

The detail structure, the applied principle, the function and theeffectiveness of the present invention can be more fully understood withreference to the following description and accompanying drawings, inwhich:

FIG. 1 is a disassembled perspective view of a preferred embodiment of acooling fan with dynamic and static blades according to the presentinvention;

FIG. 2 is a disassembled perspective view similar to FIG. 1 illustratingthe preceding embodiment being projected from another direction;

FIG. 3 is a perspective view of the preceding embodiment;

FIG. 4 is a sectional view of the preceding embodiment;

FIG. 5 is a sectional view similar to FIG. 4 illustrating another typeof the hub thereof;

FIG. 6 is a disassembled perspective view of another preferredembodiment of a cooling fan with dynamic and static blades according tothe present invention;

FIG. 7 is a perspective view of the preceding embodiment;

FIG. 8 is a disassembled perspective view similar to FIG. 6 illustratingthe preceding embodiment being projected from another direction;

FIG. 9 is an assembled perspective view illustrating the precedingembodiment being projected from another direction;

FIG. 10 is a sectional view of the preceding embodiment; and

FIG. 10 a is an enlarged diagram of the part of dash circle in FIG. 10.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1 to 4, the first preferred embodiment of a coolingfan with dynamic and static blades according the present inventionincludes a fan 11 and at least a static blade device 12. The fan 11 hasa fan frame 111 with a hollow passage 112 and the passage 112 providesan inlet 113 at a side of the fan frame 111 and an outlet 114 at anotherside of the frame 111. A bearing seat 115 is disposed near the outlet114 with a dynamic blade 116 being movably attached to the bearing seat115.

The static blade device 12 has a hollow frame member 121 with aplurality of static blades 122 being disposed inside. Each of the staticblades 122 connects with the inner wall of the frame member 121 at anend thereof and extends to a common position, which is the center of theframe member 121 in the present embodiment, at the other end thereofrespectively to connect with a hub 123 in a way of being perpendicularto the outer wall of the hub 123. Alternatively, the other ends of thestatic blades 122 extend to the common position and join at the commonposition (not shown). The static blades 122 extrude outward the framemember 121 axially.

Besides, the fan frame 111 has receiving parts 117 such as through holesand the frame member 121 provides joining parts 124 corresponding to thereceiving parts 117. The joining parts 124 can be locks, threadedfasteners or any other engaging means such as adhesives attached to thereceiving parts 117.

The static blade device 12 is arranged to face the outlet 114 of the fan11 and mounted to the outlet 114 with the joining parts 124 engagingwith the receiving parts 117. Meanwhile, the static blades extend intothe outlet 114, that is, extend into the flow passage 112 such thatspace between the dynamic blades 116 and the static blades 122 isreduced and the fluid passes through the static blades 122 withoutdecreasing kinetic energy of the fluid after passing through the dynamicblades 116. Further, comparing to the prior art, the fan of the presentinvention is more capable of allowing the fluid flowing along the axialdirection of the fan in addition to increasing fluid pressure.

Furthermore, the static fan device 12 is available for the fan 11 beingjoined to a radiator or the like, that is, the frame member 121 of thestatic blade device 12 provides joining parts corresponding to theradiator or the like. The joining parts can be locking pieces, threadedfasteners or any other engaging devices as well (not shown). Besides,the static blades 122 can be either integrally made with the framemember 121 and/or the hub 132 or an independent piece.

In addition, the hub 123 of the static blade device 12 can be hollowexcept solid from standpoint of material reduction. The outer wall ofthe hub 123 can be provided a conical shape as shown in FIG. 5 for thefluid being guided to concentrate toward the shaft thereof.

Referring to FIGS. 6 to 10 and FIG. 10 a, another embodiment of acooling fan with dynamic and static blades according the presentinvention is illustrated. The entire structure and function almost thesame as the first embodiment so that the identical parts are designatedwith the same numerals and no details will be described further. Thedifference of the present embodiment is in that the hollow fame member121 opposite to a side of the fan frame 111 provides a protruding bafflepart 125 corresponding to the flow passage 112 and the baffle part 125is mounted to the fan 11 with the static blade device 12 such that thebaffle part 125 extends into the flow passage 112 to prevent from thefluid flowing outward via the joining seam between the static bladedevice 12 and the fan 11.

It is appreciated that the cooling fan with dynamic and static bladesaccording the present invention has overcome problems resided in theprior art. The static blades 122 project outward the frame member 121and that means the frame member 121 can be thinner than that in theconventional fan. The static blades 122 extending into the inlet 113 ofthe fan 11 not only increases the fluid pressure but also allows thegross thickness of the fan 11 and the static blade device 12 beingsmaller than of the prior art. Further, the baffle part 125 is capableof preventing from fluid decrease caused by overflow and keeping flowrate of the fluid into the inlet 113.

While the invention has been described with referencing to preferredembodiments thereof, it is to be understood that modifications orvariations may be easily made without departing from the spirit of thisinvention, which is defined by the appended claims.

1. A cooling fan with dynamic and static blades, comprising: a fan,having a fan frame with a hollow flow passage, the flow passage havingan inlet at a lateral side of the fan and an outlet at another lateralside of the fan frame; a support seat, being disposed near the outletand joined with a plurality of dynamic blades; and at least a staticblade device, being mounted to the outlet, providing a hollow framemember with a plurality of static blades, the static blades extendingaxially toward one of the lateral sides and into the outlet for reducinga space between the dynamic blades and the static blades.
 2. The coolingfan with dynamic and static blades as defined in claim 1, wherein thefan frame has a plurality of receiving parts and the frame memberprovides a plurality of joining parts corresponding to the receivingparts.
 3. The cooling fan with dynamic and static blades as defined inclaim 1, wherein the joining parts are locking pieces, threadedfasteners or the like to engage with receiving parts.
 4. The cooling fanwith dynamic and static blades as defined in claim 1, wherein the staticblade device is mounted to a radiator with the fan.
 5. The cooling fanwith dynamic and static blades as defined in claim 4, wherein the framemember provides a plurality of joining parts for being joined to theradiator.
 6. The cooling fan with dynamic and static blades as definedin claim 5, wherein the joining parts are locking pieces, threadedfastener for being joined to the radiator.
 7. The cooling fan withdynamic and static blades as defined in claim 1, wherein the staticblades connect with the inner wall of the frame member at an end thereofrespectively and extend toward the center of the frame member to connectwith each other at another end thereof respectively.
 8. The cooling fanwith dynamic and static blades as defined in claim 1, wherein the staticblades connect with the inner wall of the frame member at an end thereofrespectively and extend toward the center of the frame member to connectwith a hub at another end thereof respectively.
 9. The cooling fan withdynamic and static blades as defined in claim 8, wherein the hub issolid or hollow.
 10. The cooling fan with dynamic and static blades asdefined in claim 8, wherein the hub has a conical shape slanting towardthe center thereof or a cylindrical shape.
 11. The cooling fan withdynamic and static blades as defined in claim 1, wherein the framemember provides a protruding baffle part corresponding to the flowpassage at the internal circumference of a side thereof, which faces thefan frame.
 12. The cooling fan with dynamic and static blades as definedin claim 7, wherein the static blades are integrally made with the framemember or independent from the frame member.
 13. The cooling fan withdynamic and static blades as defined in claim 8, wherein the staticblades are integrally made with the frame member or independent from theframe member.